There has been a long-felt need for an adjustable clasp for interconnecting end sections of a bracelet which is quickly and easily adjustable to fit the wearer's wrist by the retail dealer as well as by the wearer. More specifically, there has been a long-felt need for such a clasp in which all of the parts as well as the assembly are durable, which can be used with bracelets of different thicknesses and which does not damage any parts by excessive pressure of the clamping means against any other part of the assembly. There has also been a long-felt need for an adjustable clasp in which the clamping means securely holds the clasp in adjusted position but which can be easily opened by the user's fingernail without a tool. In addition there has been a long-felt need for such a clasp which presents an attractive exterior appearance. Furthermore, there has been a long-felt need for such a clasp the parts of which are economical to manufacture and to assemble.
Numerous prior art clasps have been disclosed which include a clamp assembly for receiving one end section of a bracelet in slidable, adjustable relationship and a coupling assembly which is secured to another end section of a bracelet and is detachably engagable with the clamp assembly for interlocking the bracelet on the wrist of the wearer.
In many of these prior clasps, the clamp assembly has included a bottom wall joined to a pair of spaced side walls which extend substantially normal thereto, pressure plate means, means for mounting the pressure plate means between the side walls for limited movements substantially normal to the bottom wall of the clamp assembly and rigid cam-like clamping means having one end pivotally mounted between the side walls above the pressure plate means so that at least one end portion of the clamping means engages the upper surface of the pressure plate means when the clamping means is rotated about is pivotal mounting and urges at least a lower portion of the lower surface of the pressure plate into frictional engagement with the upper surface of the bracelet section which is associated with the clamp assembly, thereby securing it in an adjusted position longitudinally of the bracelet section.
The coupling assembly which is secured to the end of the bracelet section is then detachably secured to the clamp assembly so that the bracelet encircles the wrist of the wearer.
In all of these prior art clasps of which we are aware, the clamping means is rotated about a fixed pivotal axis and its end portion which engages the upper surface of the pressure plate means is rigid. The thicknesses of bracelets vary substantially and the intensity of the force exerted upon the upper surface of the pressure plate means is increased as the thickness of the bracelet is increased thereby increasing the forces exerted by the rigid end of the clamping means against the upper surface of the pressure plate when the clamping means is rotated to its closed position. Consequently these prior art clasps are restricted either to use with bracelets of substantially the same thickness or it is necessary to provide a series of clamping means having end portions of different lengths or it is necessary to provide pressure plate means of different thicknesses since the clamping means must lock the end bracelet section with which it is associated in its adjusted position or it will slip out of the clamp assembly.
Examples of such prior art clasps are disclosed in the following prior patents and unpatented prior clasp:
Heer U.S. Pat. No. 2,015,308 dated Sept. 24, 1935; Shoeninger U.S. Pat. No. 2,229,677 dated Jan. 28, 1941; Prestinari U.S. Pat. No. 2,273,218 dated Feb. 17, 1942; Mochizuki U.S. Pat. No. 3,425,104 dated Feb. 24, 1969; and Weiss U.S. Pat. No. 3,795,028, application filed Dec. 27, 1971.
A watch bracelet made by Mochizuki Mfg. Co. of Tokyo, Japan by early 1977 in which the clamping means is substantially the same as Shoeninger's clamping means and includes a rigid cam end which is forced against the upper surface of a pressure plate when rotated to closed position.
Clamping assemblies which include rigid cam ends acting directly upon a bracelet section without an intervening pressure plate are disclosed in the following publication and patent:
Mochizuki Japanese Utility Model application No. 41-110,260 published Sept. 5, 1968; and Leon U.S. Pat. No. 3,711,906 dated Jan. 23, 1973.
While Weiss U.S. Pat. No. 3,795,028 dated Mar. 5, 1974 discloses a coupling assembly 18 which includes frame means, hook shaped tongue means 58 extending outwardly from one end of the frame means and which is detachably engagable with a cross pin means 26 of the clamp assembly 16 and a cover 66 comprising side flanges pivotally attached to the frame means, he uses protuberances 24 extending inwardly from the rigid side walls of his clamp assembly for detachably holding his cover in closed position. The cover must be opened at least once a day when the wearer of the bracelet removes the bracelet from his wrist and closed at least once a day when he places the bracelet on his wrist. Consequently Weiss' protuberances which frictionally engage the flanges of his cover either soon wear out or soon wear grooves in the flanges of the cover rendering one of them inoperative to detachably secure the cover in its closed position.
While British Pat. No. 1,138,122 dated Dec. 28, 1968 discloses a bracelet which has a cover 21 having side flanges 19, 20 which are pivotally secured to a bracelet section 1 and the side flange 20 has an inwardly extending detent 22 engagable in the open end 12 of the part 4, both the top wall of the part 4 and the flange 20 are rigid so that either the detent or the end wall soon wear rendering them inoperative to hold the cover in its closed position.
Examples of other prior art coupling assemblies having covers which have not satisfied the long-felt need are:
Mochizuki Japanese Utility Model application 41-110260 published Sept. 5, 1968; Mochizuki U.S. Pat. No. 3,425,104 dated Feb. 4, 1969; Leon U.S. Pat. No. 3,711,906 dated Jan. 23, 1973; A watch bracelet made by Mochizuki Mfg. Co. of Tokyo Japan by early 1977; and Mochizuki Japanese Utility Model application 51-89575 published Jan. 24, 1978.
The above described prior art is the closest prior art of which we are aware to an adjustable clasp for interconnecting end sections of a bracelet on the wrist of a wearer embodying our invention as described and claimed in this application.